OM System M.Zuiko 40-150mm F/4 PRO Lens Review

We are now looking at the second of the f/4 PRO lenses that offer a less expensive and more compact form factor than the f/2.8 versions. The 12-45mm f/4 PRO has already been reviewed, so now here is the M.Zuiko Digital 40-150mm f/4 PRO, with its "35mm equivalent" field of view of 80-300mm. Let's take the 20MP OM System OM-5 camera body and see how we get on, not only in the technical tests but also out in the field.

OM System M.Zuiko 40-150mm f/4 PRO Handling and Features

Olympus, and from now on OM System, lenses have always looked well made, like beautiful jewels, compact and yet sturdy. It is easy to see their appeal for travel in particular. The new lens is as compact as expected, measuring up at 68.9mm in diameter and 99.4mm in length. The lens has to be extended for use, in its parked position all functions being locked. The camera will not let us proceed until the lens is extended to its click stop at 40mm. Thereafter, zoom and focus are internal, the lens does not extend further nor does the front element rotate. Weight is in keeping with the svelte dimensions, at just 382g.

Despite the light construction, the lens feels sturdy enough and in fact, is sealed to IP53 standard. It is good to see OMDS being more specific than most regarding the degree of splashproof construction and sealing against dust. Inclement weather will not stop the OM System photographer from carrying on shooting, which is good as colours do take on a vibrant appearance in light rain. The operational temperature range of the camera and lens are also specified, down to -10C and up to +40C.

A generously sized round lens hood is provided, and this bayonets cleanly and positively into place. It is locked into position by a small, slightly recessed, catch that is not vulnerable to being accidentally pressed. Within the bayonet fitting for the hood is a conventional 62mm filter thread.

The slim, but not too slim, focusing ring can be active in AF, and this is selected as appropriate in the menus. The focusing ring is electronic and utterly smooth, with a good tactile feel that is not too loose. AF is almost silent, very fast and also accurate. Focusing is down to 0.7m, or 2.3 feet, for a maximum magnification of 0.21x. OMDS also quote a “35mm-equivalent” magnification of 0.41x, which is approaching half-life size.

The wide zoom ring is clearly marked at 40mm, 50mm, 70mm, 100mm and 150mm. The settings are accurate. The 40-150mm range has a “35mm equivalent” field of view of 80-300mm, which is a very useful range, being perfect for everything from portraits to wildlife. The f/4 aperture is a little restricting for some applications, but not as much as we might expect as many zoom lenses are not as fast as this one. The MFT format also lends itself well to giving plenty of depth of field, which might be considered a good thing, although there are some photographers who may find that a disadvantage and no doubt they will be looking for much faster lenses to make up for it.

Optical construction is 15 elements in 9 groups, including 2 ED (Extra Low Dispersion), 1 Super ED, 1 HR (High Refractive Index) and 2 Aspherical. ZERO (Zuiko Extra-Low Reflection Optical) coating is utilised to reduce or eliminate reflections and this is augmented by a Fluorine coat on the front element to repel dust, grease and moisture. The diaphragm comprises 7 blades

There are no other controls on the lens as everything is handled via the camera body, including IS as there is no stabilisation included within the lens itself. Handling is a breeze as there is really nothing to interfere with the photography. The OM-5 itself has plenty of dials and buttons to customise the user experience to suit different approaches and styles.

So far so good, but how does it all perform? Let's find out.